1. Field of the Invention
The present invention relates to an image pickup apparatus enabling shooting and display of two dimensional and three dimensional images.
2. Description of the Related Art
In recent years, portable apparatuses equipped with a shooting function, such as a digital camera, have overcome the problem of shooting various types of scenes, which such portable apparatuses have been weak at, using image processing. Also, in recent years, in the film industry, there has been a trend of introduction of 3D (three-dimensional) effect making much of realistic sensation, and following the trend, the television industry has the tendency of 3D-display apparatuses becoming popular.
Among the consumer image shooting apparatuses such as digital cameras, apparatuses enabling 3D shooting have been developed. There are a wide variety of proposals for a method for shooting and recording an image with stereoscopic information included and reproducing and viewing such image. For example, Japanese Patent Application Laid-Open Publication No. 2006-165601 discloses a technique in which incoming light from a lens is divided into a plurality of light beams and then the light beams are made to be incident on a plurality of image pickup devices having different incidence directional characteristics, thereby generating images with parallax.
Also, for example, Japanese Patent No. 4225768 discloses an apparatus including correction means for correcting an error (inclination) and/or positional misalignment in the vertical direction between horizontally-arranged images for both eyes according to the display means.
Although there are various kinds of factors for a human to have a stereoscopic sensation, in general, it has been said that a human has a stereoscopic sensation based on information such as binocular parallax, motion parallax, binocular vergence, focus and relative size. From among these pieces of information, binocular parallax, which is the largest factor for getting a stereoscopic sensation, is often used in a method for artificially providing a stereoscopic image.
As described above, for enabling provision of a stereoscopic vision, it is necessary to pick up a right-eye image and a left-eye image, that is, at least two image having parallax according to the viewpoints of both left and right eyes. The right-eye image and left-eye image are images having displacements from each other according to the parallax. Thus, unless camera shooting is performed while viewing 3D display, a desired view angle is not necessarily obtained.
Furthermore, there is a difference between stereoscopic sensation a human has with his/her bare eyes and stereoscopic sensation provided by a shot image due to various causes such as the distance between the right-eye and left-eye lenses and the distance to the subject. Accordingly, in order for a user to perform shooting so as to achieve desired stereoscopic effect, it is necessary to perform the camera shooting while viewing 3D display.
Also, in 3D shooting, two image pickup apparatuses, that is, an image pickup apparatus for picking up a right image and an image pickup apparatus for picking up a left image. Furthermore, an image pickup apparatus that obtains a 3D image by means of such one image pickup apparatus has been developed. The image pickup apparatus is provided with one image pickup device to form optical images from two image pickup lenses, that is, right-eye and left-eye pickup lenses, on the image pickup plane of such one image pickup device.
In such image pickup apparatus, in order to enhance the quality of 3D display, it is important to display two 3D images aligned with each other. In the apparatus disclosed in Japanese Patent Application Laid-Open Publication No. 2006-165601, correction is performed according to the displacement between the left and right images.